Electric switch



Aug. 20, 1929. J. D. HILLIARD ELECTRIC YwI'rcH Filed Oct. 23.

'Figl.

Invenfo Patented Aug. 20, 1929.

UNITED STATES 1,725,641 PATENT OFFICE.

JOHN D. EILLIABD, 0F SCHEJ'ECTADY,'NEW YORK, ASSIGNOB TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC SWITCH.

Application filed October 23, 1926. Serial- No. 143,755.

My invention relates to electric switches of the type having main current carrying contacts and separate auxiliary or arcing contacts which, when the switch opens, separate subsequently to the main contacts and between which the'final break in the circuit is made. An object of my invention is to rovide an improved construction of switc of this type whereby better insulation of the live parts of the switch may be efiected and all possibility of an open are at the main contacts is avoided.

My invention will be better understood from the following description taken in connection with the accompanying drawing, and its scope will be pointed out in the appended claims.

Referrin to the drawing, Fig. 1 shows a side elevation partly in section of a switch embodying my invention, and Fig. 2 is a cross-sectional view taken on line 22 of Fig. 1.

I have shown the switch supported on a plate 1 by means of two insulator bushings 2- through which extend the connecting studs 3 having nuts 4 and comprising the switch terminals. Each bushing supports a pressure vessel 6 which preferably is a steel shell whose top is closed b the cover 7 held down by the rods 8 threade into the contact clamp 9. The latter has a central 0 ening into which is secured the contracted ottom portion 10 of the vessel and is itself secured to the contact head 11 on the upper end of the stud by a suitable strap 11' an eye bolt and nut. Firmly secured in the bottom of the vessel 6 is the fixed auxiliary contact 12 in which engages the movable auxiliary contact rod 14. The two contact rods 14 extend out through the tops of the vessels through insulators 15 and are joined together by the yoke 16. Operating rod 18 passes through the yoke and at that point carries a spool 19 having sliding engagement with the yoke and providing acertain amount of lost motion between the rod and the yoke. The compression spring 20 between the yoke and the upper flange of the spool resilientl presses the yoke toward the lower'fiange ot t e spool. The vessels 6 are shown provided with separating and cooling chambers 21 to the tops of which connect discharge pipes 22. I

Arranged between the two vessels 6 is a third vessel 25 preferably of insulating material, as shown, in which vessel the main current-carrying contacts separate in an insulating liquid. The vessel 25 may be of molded lnsulating material in opposite sides near the bottom of which the main fixed contacts 26 may be molded. The vessel'is arranged so that these contacts are directly opposite the contact clamps 9 and are secured directly therewith by bolts 27. As so constructed the vessel 25 is supported by its main contacts 26 andthe contact clamps 9. The vessel contains a sultable insulating liquid 28 and has a cover 29 through an opening in which slides the operatlng rod 18. The main movable contact or bridging member 30 is secured by the bolt 31 to the cross head 32 which slides vertically on the two guide pins 33. These pins are shown secured in the bottom of the vessel and are surrounded by compression springs 34 beneath the cross head to force the brid ing member 30 out of contact with the main Exed contacts 26 when the operating rod is raised. A detachable connection is rovided between the operating rod and the rid ing member by having the bolt 31 fit loosely into a bore in the end of the operating rod. In moving the switch from the position illustrated to open circuit position the operating rod in moving of the springs 34 until their movement is arrested by the heads on the guide pins, thus separating the main current carrying contacts. During this movement or a part thereupward is followed by the cross head 32 and the bridging member 30 under the influence of, the yoke 16 remains fixed, the coil spring 20 assisting in holding it in fixed position. At length the lower flange of the spool engages the yoke, the rod and operatin mechanism therefor having gained spec in the meantime, and now the yoke with the connected auxiliary contact rods 14 rise as a unit to eflect the final quick break of the circuit.

This construction permits the main contacts to separate before the auxiliary contact rods are moved. There is also no dan er from any arcing at the main contacts and 1nsulation of the live parts of the switch are simplified and facilitated.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. An electric switch comprising spaced ressure vessels ada ted to contain insulatthe top thereof, a yoke member connecting the movable contact rods, a separate vessel adapted to contain insulating liquid arranged between said vessels having main fixed contacts therein arranged opposite and connected to the respective auxiliary fixed contacts, a main movable contact arranged to bridge said main fixed contacts, means limiting the open circuit movement of said main movable contact and an operating rod arranged to make engagement at one end with said main movable contact and to have an operative connection at an intermediate point with said yoke member.

2. An electric switch comprising a pair of spaced insulator bushings, a stud in each bushing, a pressure vessel carried by each bushing adapted to contain insulating liquid, a movable contact rod extending through the top anda fixed auxiliary contact in the bottom of each vessel, means comprising con- 3. An electric switch comprising a pair of spaced pressure vessels each adapted to contain insulating liquid and cooperating fixed and movable auxiliary contacts immersed therein, a separate vessel of insulating material arranged between said vessels and adapted to contain insulating liquid, fixed main contacts therein connecting respectively with said fixed auxiliary contacts, a movable main contact bridge therein, guiding means for said bridge, resilient means for moving the bridge to open circuit position, a yoke connecting the movable auxiliary contacts, an operating rod connected to said yoke and said bridge, a lost motion connection between the yoke and the rod and resilient means for taking up the lost motion in one direction,

4. An electric switch comprising a vessel adapted to contain insulating liquid, spaced fixed contacts therein, a cooperating movable bridging contact, a cross head secured thereto and arrangedv transversely thereof, guide pins for said cross head spaced from the fixed contacts, means for resiliently forcing the brid ing contact away from the fixed contacts, an an operating rod detachably connected to the cross hea In witness whereof, I havehereunto set my hand this Qst da of October, 1.926;

JO N D. HILLIARD. 

